Fuse device



Oct. 12 3.

W. O. SC TZ FUSE DEVICE June 1 INVENTOR V W/zmu 0 J'c/Mrz ATTO Y.

W. O. SCHULTZ FUSE DEVICE I Oct. 12; 1943.

Filed June 10, 1942 5 Sheets-Sheet 2 l/l/hl/l/l/Z VIII/11111114 INVENTORMum/14 0 Jamrz ATTKQNEX Oct. 12, 1943. w. o. SCHULTZ FUSE DEVICE FiledJune 10, 1942 3 Sheets-Sheet 3 I INXIIENTOR. Mum/n 0. Jaw/z rz BY I 2 A4) AT ORNEY.

I Patented Oct. 12, 1943 I FUSE DEVICE William 0. Schultz, southMilwaukee, Wis., assignor to Line Material Company, South Milwaukee,Wis., a corporation of Delaware Application June 10, 1942, Serial No.446,464

14 Claims.

This invention relates to fuse devices.

Objects of this invention are to provide a fuse device which employs afuse tube open at both ends and which has a headed fuse link so arranged that the head of the fuse link closes one end of the fuse tube,and in which the head of the fuse link is adapted to be blown directlyaway from the end of the fuse tube in the event of a violent evolutionof gas upon rupture of the fuse link so that the fuse tube will bevented at both ends.

Further objects are to provide an expulsion fuse device in which a fusetube is provided which is open at both ends and in which a fuse link ispositioned within the fuse tube and is provided with a head normallyclosing one end of the fuse tube, and in which stationary contacts areelectrically connected under normal conditions by means of the fuselink, and in which provision is made for the free travel of the head ofthe fuse link away from the end of the fuse tube without engaging theadjacent stationary contact so that even under violent overloadconditions no damage will be caused the stationary contact by theviolent projection of the head of the fuse link outwardly away from theend of the fuse tube, and to provide a constructionhaving thecharacteristics enumerated above in which the head of the fuse link hasgood and positive electrical contact with the adjacent electricallyconducting portion of the fuse device.

A furtherspecific object of this invention is to provide an expulsionfuse device in which the fuse tube is open at both ends, one end beingclosed by the head of the fuse link and the head of the fuse link beinggripped in such a manner that under light overloads the head of the fuselink will not be blown off and the action of the fuse tube will be thatof a fuse tube open at one end only to thereby assist in the speedyclearing of the circuit inside the fuse tube, the construction beingsuch that under heavy overloads the head of the fuse link is blown fromthe fuse tube to' thereby provide venting of the fuse tube at both ends,the device therefore having both the characteristics of an expulsionfuse tube open at one end only for light overloads and vented at bothends for heavy overloads, whereby the safe rupturing capacity of theapparatus is materially increased.

Further objects of this invention are to provide a fuse construction inwhich gripping fingers are carried by the terminal. of the fusetube andare arranged to grip different sized heads 1 of fuse links, the grippingfingers being so constructed that they have a high degree of resiliencyand consequently can adjust themselves to grip fuse link heads ofmaterially diiferent sizes.

In greater detail, objects of this invention are to provide a fuseconstruction in which the terminal of the fuse tube is provided with areduced neckagainst which the head of a headed fuse *link is adapted tobear and to provide looped gripping fingers secured on opposite sides ofthe terminal of the fuse tube and having gripping portions on oppositesides of the reduced neck of the fuse tube, the looped gripping fingersin certain forms of the invention being provided with laterallyprojecting manipulating portions which may be squeezed towards eachother to thus open the gripping portions of the gripping fingers andallow the free positioning of the head of a fuse link,

Further objects are to provide a construction in which the head of thefuse link and the fingers are positioned in spaced relation to thestationary contact so that upon violent overload the head of the fuselink will be projected from, and the blast of gases willoccur at a pointspaced from the stationary terminal, thereby avoiding damage to thestationary contact, the fuse tube being so arranged that it will dropoutwardly from operative to inoperative position.

after the circuit has been interrupted within the fuse tube.

Embodiments of the invention are shown in the accompanying drawings,inwhich:

Figure 1 is a View of one form of the invention, such view being partlyin section and partly broken away.

Figure 2 is a view, partly in section, such section being taken alongthe line 22 of Figure 1.

Figure 3 is a fragmentan top View of the structure shown in Figure 1.

Figure 4 is a view looking from the front of the fuse tube shown inFigure 1.

Figure 5 is a view of a further form of the invention.

Figure 6 is a view of the structure shown in Figure 5 looking from thefront.

"Figure 7 is a view of a further form of the invention.

Figure 8 is a view of the structure shown in Figure 7 looking from thefront. H

Figure 9 is a view looking down on the structure shown in Figure 7.

Referring to the form of the invention shown in Figures 1 to 4, it willbe seen that the device is carried by an elongated insulator l which issupported intermediate its ends as shown in Figgure 1. This insulatorcarries the upper and lower stationary contact adjacent its upper andlower ends. The lower contact comprises a hood like member 2 which isprovidedwith side walls that extend down to the position shown by thedotted line indicated at 3. The lower portion of the hood like memberconstitutes two hook like portions 4 which removably receive thetrunnions 5 of the fuse link extracting lever 6. This lever is providedwith a thumb nut I on its side which clamps the leader 8 of the fuselink. The lever is provided with a rear transverse portion 9 which bearsagainst the lower contact spring 10 to secure good electrical connectionbetween the lever and such lower spring. The spring I is secured to thehood like portion 2 which is provided with a connector portion l I atits lower end.

The lever 6 is provided with a pair of side flanges between which thedownwardly extending ear ll of an arm I 3 is positioned and the lever ispivoted to such ear as indicated by the reference character M. The armI3 is rigidly secured to the fuse tube as shown and is provided with afoot l which acts as a stop to limit the upward motion of the lever.This arm, I3 is also provided with a switch receiving eyelet portion it.v

It is to be noted that when the fuse tube is in its operative positionas shown in Figure 1, the fuse link holds the lever 6 against releasingmotion. Upon rupture of the fuse link the lever 6 rocks downwardlyextracting any remaining portion of the fuse link and lowering the fusetube so that it detaches itself from the upper stationary contact aswill hereinafter appear, thereby allowing the tube to rock downwardlyand outwardly to inoperative position.

It is to be noted that the arm I3 is mounted within the hood 2 undernormal conditions and that this hood prevents the inadvertent detachmentof the trunnions 5 from the hook like members 4 until the fuse tube hasswung downwardly. Thereafter the device may be removed from the hooklike portions by a switch stick which is adapted to engage the eyeletportion IE to lift the fuse tube out of and into position.

It is to be noted from an examination of Fieure 2 that the outer end ofthe lever 6 is positioned laterally of the fuse tube so as to leave thelower end of the fuse tube wholly unobstructed. The upper stationarycontact comprises a pair of spring arms I! which are clamped to a strapl8, the strap in turn surrounding the upper end of the insulator l andbeing clamped in place by means of the bolt [9. The spring arms I! maybe roughly of U-shape and their looped port on may be clamped by meansof the bolt 20 to the inwardly turned ends 2|v of the strap la, the boltalso clamping the connector 22 in place. The spring arms H are preventedfrom separating by means of the bracing member 23 and are provided witha downwardly depressed portion 24 and with outwardly flaring endportions 25 which act as guides to guide the fuse tube into place whenit is rocked upwardly.

The fuse tube 26 is provided with an upper contact 21 which has amanipulating eyelet 28 integral therewith and which is provided withoutwardly projecting pins 29 which normally engage behind the downwardlydepressed portions 24 of the spring arms .I'I. If desired a guidingtongue and also a stop tongue 30 may be formed integrally with the uppercontact 21, the tongue 30 acting to guide the upper end of the fuse tubeinto place between the outwardly flared portions 25 of the spring armsl1 and acting to arrest the inward rockingmotion of the fuse tube byengaging the brace member 23.

The upper contact 21 of the fuse tube has a reduced neck portion 3! uponthe top of which the button head 32 of the fuse link rests. The fuselink is, as stated, provided with the flexible leader 8 and with areduced fusible section 33.

A pair of gripping spring arms are provided for gripping opposite sidesof the button head 32 of the fuse link. These spring arms may take theshape shown particularly in Figures 1 to 4, and are provided with therounded portions 34 and with inwardly slanting looped upper portions 35.The arms of the looped upper portions 35 engage opposite sides of thebutton head 32 of the fuse link and securely grip the button head andthus secure a firm electrical contact with the button head. In additionto this, they hold the button head down against the top of the reducedneck 31 of the upper contact 21 of the fuse tube.

Upon rupture of the fuse link the button head 32 remains in place undersmall overloads and a straight expulsion action occurs as the upper endof the fuse tube remains closed. However, on heavy overloads the buttonhead 32 is blown upwardly from between the gripping portions 35 of thespring arms 34 and thus allow the tube to be vented at both its upperand lower ends. It is thus possible for the device to handle largeroverloads with safety than would be the case had the upper end of thefuse tube been permanently closed. In addition to this, it is to benoted that the button head when projected outwardly from the fuse tubedoes not strike or damage any portion of the stationary contact and theblast of gases from the fuse tube does not contact the upper contact.Consequently there is no damage to the upper contact even under violentoverload conditions.

After the fuse link has ruptured and the circult has cleared within thefuse tube, the lever 8, see Figure l, rocks downwardly and lowers thefuse tube, thus allowing the pins 29 to detach themselves from behindthe depressed portions 24 of the spring arms I! and the fuse tube thendrops outwardly and downwardly to inoperative posi- 'tion.

It is to be noted that the hood portion 2 houses the spring contact l0and the lever B and the associated mechanism and prevents theaccumulation of snow and ice in this portion of the apparatus.

In refusing the device the fuse tube is removed from the hook likemembers 4 by means of a switch stick which engages the eyelet portionI5. Thereafter while the fuse tube is detached from the remainder of theapparatus, a new fuse link 15 inserted and the head is positionedbetween the members 35, see Figure 4. This is readily accomplished asthe lineman can press the portions 34 towards each other and thus spreadthe portions 35 and allow the free positioning of the button head 32ofthe fuse link. Thereafter the fuse link is secured by means of thethumb nut I to the lever 6 and the fuse tube is replaced and rocked backinto operation position, as shown in Figure 1.

In the form ofthe invention shown in Figures 5 and 6 the fuse tube isindicated at 36. It is provided with an upper terminal 31 and a pair ofspring arms 38 are secured on opposite sides of the upper fuse tubeterminal 31. They may tions of the springarms of the uppercontact.

be secured by means of screws 39 provided with washers 40, the ends ofthe spring arms 38 being inturned and clamped beneath the washers. Thesespring arms have a downwardly looped portion as indicated at 4| toprovide additional resiliency and have relatively straight upperportions 42 positioned on opposite sides of the reduced neck 43 of theupper terminal 31 of the fuse tube. These arms may extend verticallyupwardly as shown or may be slightly inwardly tapererd if" desired. Theygrip opposite sides of I the button head 32 of the fuse link.

The uppercontact 31 of the fuse tube is provided with outwardlyprojecting pins 44 which are adapted to engage beneath depressed por- Amanipulating eyelet portion 45 is formed integrally with the uppercontact 31 of the fuse tube and such upper contact may have an inwardlyprojecting rib 43, see Figure 5, which acts as a stop to engage thebracing members for the upper spring arms of the stationary contact.

Upon rupture of the fuse link the button head 32 of the fuse link isretained in place for light overloads and a straight expulsion actionoccurs. However, under heavy overloads the button head blows driectlyupwardly away from the fuse tube.

In the form of the invention shown in Figures '7, 8 and 9 the fuse tubeis indicated at 41 and its upper contact at 48. This upper contact isprovided with a manipulating eyelet portion 49 and a reduced neckportion 50 and with a stop portion 5! located on the inner side thereofand corresponding to the stop portion 46 of Figure 5. The upper contact48 of the fuse tube is also provided with a pair of outwardly projectingpins 52 which are adapted to be positioned beneath the spring arms ofthe upper contact, as previously described.

The fuse gripping means comprises a pairof spring arms 53 which havetheir ends secured beneath the washers 54 by means of screws 55. Thesespring arms 53 extend upwardly and inwardly and are provided withportions 56 which engage opposite sides of the button head 32 of thefuse link. The arms 53 extend laterally as indicated at 51 and 58with'the portion 51 located below the plane of the portion 58.

These portions 51 and. 58, as shown most clearly in Figure 9, constitutelaterally projecting, looped, manipulating portions which are adapted tobe pressed inwardly by the operator when it is desired to clamp thebutton head of a new link in place. It is to be noted that the portionsof the spring arms which engage the button head 32 are located at spacedpoints around the button head. The looped portions 51 and 58 have theirparallel side portions spaced sufficiently far apart to allowthe freepassage therethrough of the button head 32 of the fuse link.

When the fuse link is ruptured under light overloads, the button head isretained in place and the device operates as a straight expulsion fusetube. However, when a heavy overload occurs, the button head 32 is blowndirectly outwardly from the fuse tube without damage to the upperstationary contact and the fuse tube is thus vented at both ends.

In all forms of the invention it is intended that the spring arms whichengage the button head of the fuse link have sufficient resiliency toallow fuse links with difierent sized button heads to be employed, thelarger size of the button heads having been shown in the different formsillustrated.

It will be seen that novel forms of fuse devices have been shown inwhich provision is made for directly gripping the side edges of thebutton head or other shaped head of a fuse link to retain the head inplace for small overloads and to allow the head to be blown off forheavy overloads.

It will be seen further that in the first and last forms of theinvention the construction issuch that the operator can squeeze portionsof the button head gripping members towards each other and thus spreadthem apart to allow the free positioning of a new fuse with a new buttonhead. In the second form of the invention shown in Figures 5 and 6, theoperator spreads the spring gripping members apart when he forces thebutton head of the fuse link into place.

It will be seen further that a very good electrical contact is obtaineddirectly with the head of the fuse link and that this result is obtainedthrough the use of a relatively simple construction.

Although this invention has been described in considerable detail, it isto be understood that such description is intended as illustrativerather than limiting, as the invention may be variously embodied and isto be interpreted as claimed.

1 claim:

1. In a fuse construction, stationary terminals, a fuse "tube havingboth ends open and having a terminal adjacent one end normallyelectrically connected to one of the stationary terminals, a fuse linkextending through the fuse tube and having a head at one end normallyclosing one end of said fuse tube and connecting the other stationaryterminal with the terminal of the fuse tube, and resilient means carriedby the terminal of the fuse tube for gripping the head of the fuse link,the gripping portion of said resilient means having a substantial rangeof movement to grip heads of different sizes.

2. In a fuse construction, stationary terminals, a fuse tube having bothends open and having a terminal adjacent one end normallyelectricalhaving a head at one end normally closing one end of said fusetube and connecting the other stationary terminal with the terminal ofthe fuse tube, and resilient means carried by the terminal of the fusetube for gripping the sides of the head of the fuse link, the grippingportion of said resilient means having a substantial range of movementto grip heads of different sizes.

3. In a fuse construction, stationary terminals, a fuse tube having bothends open and having a terminal adjacent one end normally electricallyconnected to one of the stationary terminals, a fuse link extendingthrough the fuse tube and having a head at one end normally closing oneend of said fuse tube and connecting the other stationary terminal withthe terminal of the fuse tube, and resilient means carried by theterminal of the fuse tube for gripping the head of the fuse-link, thegripping portion of said resilient means having a substantial range ofmovement to grip heads of different sizes, the gripping portion of saidresilient means leaving a substantially unobstructed space beyond thehead of the fuse link, whereby the head may be blown outwardly whensufficient pressure is developed in the fuse tube upon rupture of thefuse link on heavy overload.

4. In a fuse construction, stationary terminals, a fuse tube having bothends open and having a terminal adjacent one end normally electricallyconnected to one of the stationary terminals, a fuse link extendingthrough the fuse tube and having a head at one end normally closing oneend of said fuse tube and connecting the other stationary terminal withthe terminal of the fuse tube, and resilient gripping means havinglooped portions, said gripping means being carried by the terminal ofthe fuse tube for gripping the head of the fuse link, the loopedportions of said gripping means providing increased resiliency for saidgripping means.

5. In a fuse construction, stationary terminals, a fuse tube having bothends open and having a terminal adjacent one end normally electricallyconnected to one of the stationary terminals, a fuse link extendingthrough the fuse tubeand having a head at one end normally closing oneend of said fuse tube and connecting the other stationary terminal withthe terminal of the fuse tube, and resilient gripping means havinglooped portions, said gripping means being carried by the terminal ofthe fuse tube for gripping the head of the fuse link, the loopedportions of said gripping means providing increased resiliency for saidgripping means, the head of the fuse link being gripped on its sides bysaid gripping means, whereby the head of the fuse link may be blownoutwardly when sufficient pressure is developed, in the fuse tube uponrupture of the fuse link on heavy overload.

6. In a drop-out fuse construction, an upper and a lower stationaryterminal, a fuse tube having both ends open and having a terminaladjacent its upper end normally electrically connected to andinterlocking with the upper stationary terminal, a fuse link extendingthrough the fuse tube and having a head at its upper end normallyclosing the upper end of said fuse tube and connecting the lowerstationary terminal with the terminal of said fuse tube, said headnormally bearing against the terminal of said fuse tube, resilientgripping means carried by the terminal of said fuse tube and havinglooped portions and having gripping portions spaced from the loopedportions for gripping the head of the fuse link, and lever meansnormally supporting the lower end of said fuse tube, said lever meansbeing restrained bysaid fuse link and releasing said fuse tube fordrop-out motion upon rupture of said fuse link.

'7. In a drop-out fuse construction, an upper and a lower stationaryterminal, the upper stationary terminal having a pair of spaced arms, afuse tube having both ends open and having a terminal adjacent its upperend normally I positioned between the arms of said upper stationaryterminal and interlocking with said arms, a fuse link extending throughthe fuse tube and having a head at its upper end normally closing theupper end of said fuse tube and connecting the lower stationary terminalwith the terminal of the fuse tube, resilient gripping means forgripping the sides of the head of the fuse link. said resilient grippingmeans having looped portions for increasing the resiliency of saidresilient gripping means, and means adjacent the lower. end of said fusetube controlled by said fuse link for normally holding said fuse tube ininterlocking relation to said upper stationary terminal, said meansreleasing said fuse tube for drop-outmotion upon rupture of said fuselink.

8. In a drop-out fuse construction, an upper and a lower stationaryterminal, theupper stationary terminal having a pair of spaced arms, afuse tube having both ends open and having a terminal adjacent its upperend normallypositioned between the arms of said upper stationaryterminal and interlocking with said arms, a fuse link extending throughthe fuse tube and having a head at its upper end normally closing theupper end of said fuse tube and connecting the lower stationary terminalwith the terminal of the fuse tube, resilient gripping means forgripping the sides of the head of the fuse link, said resilient grippingmeans having looped portions for increasing the resiliency of saidresilient gripping means, said looped portions being located below thearms of said upper stationary terminal, and means adjacent the lower endof said fuse tube controlled by said fuse link for normally holding saidfuse tube in interlocking relation to said upper stationary terminal,said means releasing said fuse tube for drop-out motion upon rupture ofsaid fuse link.

9. In a fuse construction, stationary terminals, a fuse tube having bothends open and having a terminal adjacent one end normally electricallyconnected to one of the stationary terminals, a fuse link extendingthrough the fuse tube and having a head at one end and connecting theother stationary terminal with the terminal of the fuse tube, the headof said fuse link normally, closing one end of said fuse tube, andgripping means carried by the terminal of the fuse tube for gripping thesides of the head of the fuse link, the gripping means having loopedportions to provide resiliency, said gripping means holding said head intube closed position on light overloads and said head being blownoutwardly upon heavy overloads to thereby vent said fuse tube at bothends upon heavy overloads.

10. In a fuse construction, stationary terminals, a fuse tube havingboth ends open and having a, terminal adjacent one end normallyelectrically connected to one of the stationary terminals, a fuse linkextending through said fuse tube and having a head at one end normallyclosing one end of said fuse tube and connecting the other stationaryterminal with the terminal of the fuse tube, and resilient grippingmeans carried by the terminal of the fuse tube for gripping the sides ofthe head of the fuse link, said means having oppositely loopedprojecting portions, whereby said projecting portions of said grippingmeans may be squeezed towards each other to open said gripping means forthe free passage of the head of the fuse link.

11. In a fuse construction, stationary terminals, a fuse tube havingboth ends open and having a terminal adjacent one end provided with anoutwardly projecting reduced neck portion, theterminal of said fuse tubebeing normally electrically connected to one of the stationaryterminals, a. fuse link extending through the fuse tube and having ahead at one end normally bearing-against the neck portion of theterminal of said fuse tube and connecting the other stationary terminalwith the terminal of said fuse tube, and resilient gripping means havinggripping portions on" opposite sides of said neck portion for grippingthe head of the fuse link and having looped portions and terminating inattached portions attached to the terminal of the fuse tube.

12. In a fuse construction, stationary terminals, a fuse tube havingboth ends open and having a terminal adjacent one end normallyelectrically connected to one of the stationary terminals, the terminalof said fuse tube having a reduced neck portion projecting outwardly, a

fuse link extending through the fuse tube and having a head atone endnormally engaging the outer end of the neck portion of the terminal ofsaid fuse tube, and a pair of resilient gripping means, each resilientgripping means being anchored on one side of the terminal of said fusetube and extending across to the other side of the terminal of said fusetube and having a gripping portion'on said last mentioned side forgripping the head of the fuse link.

13. In a fuse construction, stationary terminals, a fuse tube havingboth ends open and having a terminal adjacent one end normallyelectrically connected to one of the stationary terminals, the terminalof said fuse tube having a reduced neck portion projecting outwardly, afuse link extending through the fuse tube and having a head at one endnormally engaging the outer end of the neck portion of the terminal ofsaid fuse tube, and a pair of resiliside of the terminal of the fusetube to which it is secured for gripping the side of the head of thefuse link, the gripping portions of said gripping means being located onopposite sides of the neck of the terminal ofsaid fuse tube.

14. In a fuse construction, stationary terminals, a fuse tube havingboth ends open and having a terminal adjacent one end normallyelectrically connected to one of the stationary terminals, the terminalof said fuse tube having a reduced neck portion projecting outwardly, afuse link extending through the fuse tube and having a head at one endnormally engaging the outer end of the neck portion of the terminal ofsaid fuse tube, and a pair of resilient gripping means, each grippingmeans having a portion secured to one side of the terminal of the fusetube and having a gripping portion on the same side of said terminal forgripping the side of the head of the fuse link and each gripping portionhaving a manipulating portion proiecting across to the other side of theterminal of the fuse tube.

WILLIAM O. SCHULTZ.

